Air drier and cleaner

ABSTRACT

Compressed air from a line is passed through a horizontal threecompartment casing in which the sense of swirl of the air is reversed from compartment to compartment, the swirling air passing through a screen which aids in separating water and other foreign matter, the air being returned to the line with its original sense of swirl.

United States Patent Hamilton et al.

[ Nov. 13, 1973 AIR DRIER AND CLEANER Inventors: Norman V. Hamilton;Ronald Lehoux, both of Timmins, Ontario,

Canada Assignee: Harnlou Limited, Timmins, Ontario,

Canada Filed: Apr. 14, 1971 App]. No.: 133,866

Foreign Application Priority Data Apr. 21, 1970 Canada 80658 US. Cl55/345, 55/419, 55/458, 55/460, 55/461, 55/466 Int. Cl Bold 45/12 Fieldof Search 55/92, 235-238, 55/348, 349, 419, 452, 458, 459, 460, 461,466; 261/79 A [56] References Cited UNITED STATES PATENTS 1,847,4523/1932 Vaughn 55/238 3,048,956 8/1962 Lundy et al... 3,273,316 9/1966Ross 3,641,745 2/1972 Moore 55/345 Primary ExaminerBernard NozickAttorney-Maybee & Legris [57] ABSTRACT Compressed air from a line ispassed through a horizontal three-compartment casing in which the senseof swirl of the air is reversed from compartment to compartment, theswirling air passing through a screen which aids in separating water andother foreign matter, the air being returned to the line with itsoriginal sense of swirl.

8 Claims, 6 Drawing Figures AIR DRIER AND CLEANER BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to the dryingand cleaning of compressed air.

2. Description of the Prior Art Compressed air flows through acompressed air line with a swirling motion, the sense of swirl in thenorth ern hemisphere being clockwise when looking in the direction oftravel, or counterclockwise when looking upstream. For many uses it isdesirable that the air be relatively free of water and other foreignmatter. Compressed air supplied to underground workings in mines, atpressures up to about 125 p.s.i., may accumulate a substantial amount ofmoisture because of temperature variations, and may also collect gritand rust particles because of the dirty surroundings, abusive treatmentof the lines, and the like. Cyclones are well known for drying air atrelatively low pressures, but conventional cyclones are of relativelylarge size and incapable of withstanding the pressures, abrasive actionof grit, and other abuses that occur in many mining environments.

SUMMARY OF THE INVENTION The present invention provides a drier andcleaner that is of relatively simple construction, and that can becompact and rugged. The drier has a number of compartments in which thedirection of swirl of the incoming compressed air is varied, the driedair being delivered back to the line with the same sense of swirl as ithad when it entered the drier. The drier has no moving parts, isarranged with its axis generally horizontal, and has a screen throughwhich the air, as it swirls, passes downwardly and then upwardly, withdischarge of foreign matter below the screen.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of theinvention is illustrated in the accompanying drawings in which: 7

FIG. 1 is a longitudinal section through an air drier and cleaner;

FIG. 2 is a cross-section as seen at A- A in FIG. 1;

FIG. 3 is a cross-section as seen at 3-8 in FIG. 1;

FIG. 4 is a cross-section as seen at C-C in FIG. 1;

FIGQS is a cross-section as seen at D--D in FIG. 1; and

FIG. 6 is a plan view of part of a drier screen.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drier illustrated consistsof a casing having a tubular wall 1 closed at its ends 2 and divided bytwo transverse partitions 3 into a first chamber 21, a central chamber22 and a third chamber 23. These chambers are substantially circular incross-section, and have a common horizontal axis 24. The chambers havedownward extensions 21 22', 23' respectively which distort theircircular cross-sections and from which foreign matter can be dischargedas described later.

The casing wall 1 is conveniently constructed from a larger upper pipe12 and a smaller lower pipe 11, these pipes being welded together alonglines 13, with a horizontal perforated plate 4 between them to serve asa screen above the extensions 21', 22' and 23'.

Leading to the first compartment 21 is an inlet 31 on the axis 24. Bymeans of a pipe coupling 9 welded to the end wall 2, a compressed airline (not shown) can be connected to deliver compressed air to the inlet31 and thus into the chambers which are of larger transverse sectionthan the line. The compressed air in the line will normally have aswirling motion indicated by the arrow 100, i.e., counterclockwise whenlooking upstream. Leading from the line inlet 31, and located within thechamber 21, is a inlet elbow 5.

As shown in FIG. 2, the inlet elbow 5 has its outlet 5a directedradially upwardly into the first chamber 21 at an angle 12 clockwisefrom the vertical (looking upstream towards the line inlet). Thisarrangement is found to cause the air to travel through the chamber 21in a counterclockwise direction (looking downstream) as indicated by thearrow 101 in FIG. 1. The screen 4 extends across the lower part of thecasing in the path of the swirling air, being on a chord of the upperand truly circular portion of the chamber 21. Thus the swirling airpasses downwardly and then back upwardly through the screen 4. Most ofthe extension 21' is out of the primarily circular swirling path of theair, and solids and liquids from the air flow through an elbow 7 andpipe 8 leading from the bottom of the chamber 21 to a pipe coupling 19for connection to a drainage trap or valve.

Above the level of the screen 4 the first partition 3 (between chambers21 and 22) has four passages 32 which are located at equal intervals ona circle concentric with the axis 24. As seen in FIG. 3, one of thepassages 32 is located at an angle 40 counterclockwise (lookingupstream) from the vertical, i.e., from 12 oclock. The passages 32 serveas inlets to 90 elbows 6 which are located in the central chamber 22 andhave outlets 6a (FIG. 3) directed tangentially to the circle on whichthe passages 32 are located. The elbows 6 direct the air into thechamber 22 with a counterclockwise swirl (looking upstream), so that thesense of swirl of the air in chamber 22 is reversed from that in chamber21, as indicated by the arrow 102. Below the screen 4 in the chamber 22another discharge pipe 8 leads to the drainage coupling 19.

The second partition 3 (between the chambers 22 and 23) has fourpassages 33 identical to the passages 32, being located at equalintervals on a circle concentric with the axis 24, all at an elevationhigher than the screen 4, one passage 33 being located at an angle 40counterclockwise from 12 oclock as seen in FIG. 4. These passages 33 areinlets to elbows 16 in the chamber 23, where the elbow outlets 16a aredirected in the sense opposite to the outlets 6a, so as to impart aclockwise swirl to the air as indicated by the arrow 103. For a thirdtime the air swirls through a screen 4, with discharge of foreign matterfrom the bottom of chamber 23 via a pipe 8 to the drainage coupling 19.

The end wall 2 of the third chamber 23 has an outlet 34 which is on theaxis 24 and can be connected to the compressed air line by anothercoupling 9. For delivering the air in chamber 23 to the line, an outletelbow 15 extends into the chamber 23, and the inlet 15a to elbow 15leads radially downwardly at an angle 12 counterclockwise from thevertical when looking upstream (or clockwise from the vertical whenlooking downstream as in FIG. 5). With this disposition of the outletelbow 15 the air discharged through the outlet 34 has a swirl in thesense of the arrow 104, i.e., in the same sense as when it entered theinlet 31. If the air were delivered through the outlet with the oppositesense of swirl, it would, flowing in the line, tend to revert to itsnatural sense (counterclockwise looking upstream in the northernhemisphere), disturbing the flow in the line.

It is found that three chambers 21, 22 and 23 are sufficient to achievea high degree of purification of compressed air. If further chamberswere added, an odd number should be used so that the air emerges withthe same sense of swirl as it entered, but it is doubtful that furtherchambers are necessary for most uses.

Excellent operation is achieved with the preferred unit shown in thedrawings even if the air pressure varies considerably. The unitillustrated has no moving parts to wear out, has no filtering media tochange, and does not require adjustment. It can be of all welded steelconstruction, capable of withstanding high pressures and the abrasiveaction of solids that may be carried by the incoming air.

The angles shown in FIGS. 2, 3 and 4 are found to be suitable for a unithaving the following dimensions:

Chambers 21, 22 and 23 3 inches radius about axis 24.

Inlet 31 and outlet 34 2 inches diameter.

Passages 32 and 33 a inch diameter.

The plate 4 preferably has holes of /4 inch diameter spaced apart asshown in FIG. 6. Solids carried by the incoming air pass down throughthese holes and tend to be trapped under the screen 4. Particles ofscale or other solids larger than the holes tend to be broken up by theswirling action above the screen before passing through it, and thus donot clog the drainage system. The screen should be of sturdyconstruction with holes sufficiently large that they do not becomeplugged by solids normally encountered in the line, for example by moistsand and grit that sometimes finds its way into compressed air lines inmines.

The 12 angle shown in FIG. 2 for the elbow is not critical. To achievethe desired sense of swirl in the chamber 21 the outlet 5a could, asviewed in FIG. 2, be directed anywhere from about 1 oclock to about 4oclock; beyond 4 oclock it would be directed at the screen 4 rather thanabove it. The same applies to the inlet a as viewed in FIG. 5 (i.e.,looking downstream); putting it otherwise, looking upstream the inlet15a could be disposed in the angle between about 11 oclock and 8 oclockso as to be directed towards the. chamber wall above the screen.

The 40 angles shown in FIGS. 3 and 4 are not critical, but it is to benoted that each elbow 6, having its outlet disposed generallytangentially, is aimed to direct air between the next elbow 6 and thechamber wall, and thus past the outlet 6a of the next elbow, and thiscreates a suction helping to draw the air from chamber 21 into chamber22. The elbows 16 accomplish a similar action. The total area of thefour passages 32 is less than the area of the inlet 31; in the exampleillustrated, the four passages 32 are approximately one-half inch indiameter, so that their total area is about 0.785 sq. in., whereas thearea of the 2 inches diameter inlet 31 is about 3.14 sq. in. The airtherefore flows through the elbows 6 at relatively high velocity, andthe elbows should be of heavy duty construction to withstand theabrasive action of any solids carried in the air.

If it is desired to connect the drainage coupling 19 to a conventionalair-operated moisture trap, the flushing mechanism of the trap can tripa valve to allow a shot of air into the trap from the casing 1 through anipple 10. If simple gravity drainage from a trap or valve is desired,however, the nipple 10 is not required and can be plugged, or a gaugecan be connected thereto.

What we claim as our invention is:

1. A drier and cleaner for a compressed air line through which the air,which may carry abrasive particles, travels with a swirling motion in apredetermined sense, comprising a casing having ends spaced apart on agenerally horizontal axis, one end having a line inlet and the other endhaving a line outlet whereby the cats ing can be connected in the line,a plurality of partitions dividing the casing transversely into aplurality of generally cylindrical chambers through which the air canpass successively from the line inlet to the line outlet, the chambersbeing of larger transverse section than the line, stationary airdirecting means at the line outlet for causing the air passing to theoutlet to swirl in said predetermined sense, stationary air directingmeans in the partitions directing the air away from said axis to swirlin opposite senses in successive chambers, a screen extending chordwiseacross the lower part of each chamber and through which the swirling airin the chamber passes downwardly and then upwardly, and below the screena discharge for liquid and solid matter removed from the air.

2. A drier and cleaner as claimed in claim 1, wherein the stationary airdirecting means in the partitions comprise elbows through which the airpasses from one chamber to the next.

3. A drier and cleaner as claimed in claim 2, wherein each elbow has anoutlet aimed to direct air between the chamber wall and the next elbowto create a suction at the outlet of said next elbow.

4. A drier and cleaner for a compressed air line through which the airtravels with a swirling motion in a predetermined sense, comprising acasing having a first and a second transverse partition dividing theeasing into a first, a central and a third chamber each of substantiallycircular cross-section and having a common generally horizontal axis, aninlet elbow in the first chamber having a line inlet on said axis and anoutlet directing the air to flow through the first chamber with aswirling motion in the sense opposite to said predetermined sense, aplurality of elbows in the central chamber having inlets through thefirst partition disposed around said axis and having outlets directingthe air to flow through the central chamber in said predetermined sense,a plurality of elbows in the third chamber having inlets through thesecond partition disposed around said axis and having outlets directingthe air to flow through the third chamber in said opposite sense, anoutlet elbow in the third chamber having a line outlet on said axis anddisposed to deliver air from the third chamber to the line outlet withsaid predetermined sense of swirling motion, each chamber having, at alevel below said elbows, a generally horizontal screen in the path ofthe swirling air and, below the screen and out of the path of the air, adischarge for matter removed from the air.

5. A drier and cleaner as claimed in claim 4 wherein the elbow inletsthrough the partitions are located at equal intervals on a circleconcentric with said axis, and the outlets therefrom are directedgenerally tangentially to said circles.

6. A drier and cleaner as claimed in claim 5 wherein the total area forflow of air through eachv partition is 6 less than the area for flow ofair through the inlet eloutlet elbow has its inlet leading radiallydownwardly bow. from the third chamber at an angle counterclockwise 7. Adrier and cleaner as claimed in claim 6 wherein, from the vertical andabove the screen. looking upstream, said predetermined sense is counter-8. A drier and cleaner as claimed in claim 7 wherein clockwise, saidinlet elbow has its outlet directed at an 5 the discharge for eachchamber comprises a downward angle clockwise from the vertical (i.e., 12oclock) extension thereof.

towards the chamber wall above the screen, and said

1. A drier and cleaner for a compressed air line through which the air,which may carry abrasive particles, travels with a swirling motion in apredetermined sense, comprising a casing having ends spaced apart on agenerally horizontal axis, one end having a line inlet and the other endhaving a line outlet whereby the casing can be connected in the line, aplurality of partitions dividing the casing transveRsely into aplurality of generally cylindrical chambers through which the air canpass successively from the line inlet to the line outlet, the chambersbeing of larger transverse section than the line, stationary airdirecting means at the line outlet for causing the air passing to theoutlet to swirl in said predetermined sense, stationary air directingmeans in the partitions directing the air away from said axis to swirlin opposite senses in successive chambers, a screen extending chordwiseacross the lower part of each chamber and through which the swirling airin the chamber passes downwardly and then upwardly, and below the screena discharge for liquid and solid matter removed from the air.
 2. A drierand cleaner as claimed in claim 1, wherein the stationary air directingmeans in the partitions comprise elbows through which the air passesfrom one chamber to the next.
 3. A drier and cleaner as claimed in claim2, wherein each elbow has an outlet aimed to direct air between thechamber wall and the next elbow to create a suction at the outlet ofsaid next elbow.
 4. A drier and cleaner for a compressed air linethrough which the air travels with a swirling motion in a predeterminedsense, comprising a casing having a first and a second transversepartition dividing the casing into a first, a central and a thirdchamber each of substantially circular cross-section and having a commongenerally horizontal axis, an inlet elbow in the first chamber having aline inlet on said axis and an outlet directing the air to flow throughthe first chamber with a swirling motion in the sense opposite to saidpredetermined sense, a plurality of elbows in the central chamber havinginlets through the first partition disposed around said axis and havingoutlets directing the air to flow through the central chamber in saidpredetermined sense, a plurality of elbows in the third chamber havinginlets through the second partition disposed around said axis and havingoutlets directing the air to flow through the third chamber in saidopposite sense, an outlet elbow in the third chamber having a lineoutlet on said axis and disposed to deliver air from the third chamberto the line outlet with said predetermined sense of swirling motion,each chamber having, at a level below said elbows, a generallyhorizontal screen in the path of the swirling air and, below the screenand out of the path of the air, a discharge for matter removed from theair.
 5. A drier and cleaner as claimed in claim 4 wherein the elbowinlets through the partitions are located at equal intervals on a circleconcentric with said axis, and the outlets therefrom are directedgenerally tangentially to said circles.
 6. A drier and cleaner asclaimed in claim 5 wherein the total area for flow of air through eachpartition is less than the area for flow of air through the inlet elbow.7. A drier and cleaner as claimed in claim 6 wherein, looking upstream,said predetermined sense is counterclockwise, said inlet elbow has itsoutlet directed at an angle clockwise from the vertical (i.e., 12o''clock) towards the chamber wall above the screen, and said outletelbow has its inlet leading radially downwardly from the third chamberat an angle counterclockwise from the vertical and above the screen. 8.A drier and cleaner as claimed in claim 7 wherein the discharge for eachchamber comprises a downward extension thereof.